Caution, Drivers! Children Present: Traffic, Pollution, and Infant Health
利用加州2002-2007年数据，通过交通与天气构建工具变量，发现现代水平的颗粒物对婴儿死亡率有显著影响，尤其对早产或低体重婴儿。
We investigate the effects of automobile congestion on ambient air pollution and local infant mortality rates using data from California spanning 2002 to 2007. Constructing instrumental variables (IV) using the relationship of traffic, weather conditions, and pollutants, we show that particulate matter, even at modern levels, has large marginal effects on weekly infant mortality rates, especially for premature or low birthweight infants. We also find suggestive evidence of large effects for carbon monoxide, though results are imprecise. Finally, we check estimate sensitivity to nonclassical measurement error in local pollution and show that our IV results are robust to such concerns.